Cockatrice are Slayer monsters that require level 25 Slayer to kill. A mirror shield is required to defend against their piercing gaze, or else they will reduce your combat stats every hit, even while safe-spotting. As 20 Defence is needed to be able to wield a mirror shield, players who do not meet this requirement will not be assigned them as a task. It's worthy to note that their strength lies purely in their piercing gaze ability; with a mirror shield equipped, do not expect much of a fight. As such, not a lot of resources are necessary to hunt this monster.